Photographic emulsion layer containing pyrazoloazole coupler exhibiting improved dye light fade
US5609996A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 29, 1996 |
| Grant date | Mar 11, 1997 |
| Priority date | — |
| Expiry date | Feb 29, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C7/3825
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A photographic light sensitive silver halide emulsion layer has associated therewith a pyrazoloazole dye-forming coupler having the formula: ##STR1## wherein: R.sup.1 is a substituent bonded to the pyrazolotriazole nucleus by a fully substituted carbon atom; PA1 X is hydrogen or a coupling-off group; PA1 L is a divalent linking group; PA1 R.sup.2, R.sup.3, and R.sup.4 are independently hydrogen or substituent groups; and PA1 Z.sub.a, Z.sub.b, and Z.sub.c are independently --C(R')(R")--, .dbd.N--, .dbd.C(R')--, or --NH--, wherein R', and R" are independently H or a substituent, provided that one of either the Z.sub.a --Z.sub.b or the Z.sub.b --Z.sub.c bond is a double bond and the other is a single bond, and provided that when the Z.sub.b --Z.sub.c bond is a double bond, it may form part of a fused ring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.